1 Features
• High-efficiency, 1.5-MHz, synchronous switching
mode buck charger for single cell battery
– >90% efficiency down to 25-mA output current
from 5-V input
– Charge termination from
– Flexible JEITA profile for safe charging over
temperature
• BATFET control to support shutdown, ship mode
and full system reset
– 1.5-μA quiescent current in battery only mode
– 0.15-μA battery leakage current in ship mode
– 0.1-μA battery leakage current in shutdown
• Supports Boost Mode operation to power accesory
– Boost Mode operation supporting 3.84-V to 5.2-
V output
– >90% boost efficiency down to 100-mA boost
current for 5-V PMID
• Supports a wide range of input sources
– 3.9-V to 18-V wide input operating voltage
range with 26-V absolute maximum input
voltage
– Maximizes source power with input voltage
regulation (VINDPM) and input current
regulation (IINDPM)
– VINDPM threshold automatically tracks battery
voltage
• Efficient battery operation with 15-mΩ BATFET
• Narrow VDC (NVDC) power path management
– System instant-on with depleted or no battery
– Battery supplement when adapter is fully
loaded
• Flexible autonomous or I2C-controlled modes
• Integrated 12-bit ADC for voltage, current,
temperature monitoring
• High Accuracy
– ±0.4% charge voltage regulation
– ±5% charge current regulation
– ±5% input current regulation
• Safety
– Thermal regulation and thermal shutdown
– Input, system, and battery overvoltage
protection
– Battery, and converter overcurrent protection
– Charging safety timer

2 Applications
• Consumer Wearables, Smartwatch
• Portable Speakers, TWS Earphone
• Hearing Aid or TWS Charging Case

3 Description
The BQ25628 and BQ25629 are highly-integrated
2-A switch-mode battery charge management and
system power path management devices for single
cell Li-ion and Li-polymer batteries. The solution is
highly integrated with built-in current sensing, loop
compensation, input reverse-blocking FET (RBFET,
Q1), high-side switching FET (HSFET, Q2), lowside
switching FET (LSFET, Q3), and battery FET
(BATFET, Q4) between system and battery. The
device uses narrow VDC power path management,
regulating the system slightly above the battery
voltage without dropping below a configurable
minimum system voltage. The low impedance power
path optimizes switch-mode operation efficiency,
reduces battery charging time, extends battery life
during discharging phase, and the ultra-low 0.15-μA
ship mode current extends battery shelf life. The I2C
serial interface with charging and system settings
makes BQ25628 and BQ25629 truly flexible solutions.